Electronic circuits, such as integrated circuits and multichip modules, are coated for protection from tampering and to inhibit reverse engineering, and U.S. Pat. No. 5,366,441 to Bearinger et al. and U.S. Pat. No. 5,258,334 to Lantz et al. are illustrative of conventional coating techniques that apply a coating composition to the circuit as a liquid using a mask and then heat the coated circuit to cure the coating. The coating may consist of a silica precursor, such as hydrogen silsesquioxane resin (H-resin), and a filler. Following the teaching in Bearinger, the microcircuit die with the precursor coating is heated in a Lindberg furnace to a temperature greater than 400.degree. C. for up to six (6) hours, which converts the coating to a glass or ceramic matrix. The filler may be a material that absorbs (attenuates) x-rays to provide a coating that yields an opaque image under radiographic and/or visual inspection. The resin may simply be an opaque resin to conceal the circuit (preventing visual inspection). Lantz also employs a secondary coating that is applied using chemical vapor deposition (CVD)and/or ion beam methods. A disadvantage with these techniques, the coating mixture is applied to a partially fabricated circuit (i.e., die surface), before the die attachments, wire bonds and other circuit connections are made. Because the coating does not cover the final circuit, any electromagnetic and radiation shielding is marginal at best and ineffective for extreme conditions, such as spacecraft and nuclear facilities. Techniques like Bearinger and Lantz also require long processing times and high processing temperatures, making them unacceptably risky for coating delicate circuits and impractical for mass producing low cost coated circuits. Another drawback, specific to Lantz process, is that depositing the secondary coating requires costly, complex deposition chambers and long processing times.